The invention relates to a device for unloading a container used for transporting bulk goods, wherein the floor of the container is made up at least in part of flaps which can be tilted outwards from the interior of the container.
The unloading device is intended for use in particular in a railway hopper truck having at the longitudinal axis a center sill with foot projecting out approximately perpendicularly on each side, and sidewalls with reinforcing section at the lower edge.
Known, for example from the U.S. Pat. No. 3,949,681, is an unloading device comprising two flaps which form the floor of the truck and which touch approximately at the longitudinal axis of the truck when in the closed position. The flaps are opened outwards via a hydraulic drive for unloading purposes. In this design, however, problems arise as the whole load of the truck contents rests on the flaps, in particular close to the place where both flaps touch. Consequently, the flaps have to be held in place by a special means of suspension. Furthermore, there is no central, longitudinal beam to mount the coupling facilities on, or to improve the distribution of pressure and the stability of the truck.
Other railway trucks as, for example, shown in the German patent No. 23 58 079 are sub-divided into individual silos with the floor formed by flaps lying transverse to the long axis of the truck. Each flap is provided with its own power means so that each silo can be emptied individually at will. Apart from the fact that the central longitudinal beam is also missing here, this system is very expensive due to the individual power means for each flap.
The U.S. Pat. No. 3,805,708 shows a railway truck with longitudinal beam and unloading device parallel to the longitudinal axis. This unloading facility comprises two flaps, one of which hinges on the longitudinal beam, the other on the bottom of the sidewall. In the closed position the flaps form a funnel and are locked at the place of contact. A disadvantage here is that the total pressure from the truck contents acts on the flaps and especially on the locking facility which in turn does not feature a direct connection to a rigid element of the truck. Furthermore, some parts of the power means for the flaps are of necessity inside the truck, and are therefore exposed to possible damage by the contents during loading. Also, this arrangement of the flaps only permits unloading onto the rails lying approximately below the contact point of both flaps. This is undesireable as the wheels of the truck have to run over the residual, unloaded material as the truck is pulled away.
Revealed in the Australian patent No. 476 860 is an unloading device for a railway hopper truck with center sill having a flap on each side of the center sill and hinged to the corresponding sidewall; the flaps close onto a lower edge of the center sill or a lower edge of a run-off surface covering the center sill. The unloading device is operated hydraulically, the whole of the drive mechanism being situated inside the truck and the hydraulic piston being mounted on the center sill above the run-off surface. Due to the direct contact with the contents the drive mechanism is subjected to considerable wear. Furthermore, this arrangement only permits unloading towards the center of the truck.
The object of the present invention is to develop an unloading device which is situated outside the container interior, and is therefore not exposed to damage by the contents, and at the same time is simple to operate. This unloading facility is intended to be suitable in particular for railway hopper trucks with a longitudinal center sill, and should allow unloading on both sides of the rails. Furthermore, the disadvantages exhibited by known unloading facilities should be avoided.